An ecologist observes that a population of rabbits in a meadow has significantly increased over the past year. What is the most direct and certain explanation for this population growth?

The amount of grass and clover available for food increased.

The rabbits had more births than deaths during the year.

The number of predators in the area decreased.

The rabbits successfully migrated from another meadow.

If a biologist observes that a fish population in a lake is declining year after year, which statement must be true about the population dynamics?

The rate of deaths is consistently greater than the rate of births.

A new predator has been introduced into the lake's ecosystem.

Pollution has made it harder for the fish to reproduce successfully.

The fish have begun to migrate out of the lake to a connected river.

The deer's migration patterns and their genetic diversity.

The average weather patterns and the amount of sunlight.

The birth rate and the death rate within the population.

The types of trees in the forest and the soil composition.

The mouse population will decrease because their habitat is smaller.

The death rate of the mice will decrease, leading to a population increase.

The birth rate of the mice will increase to compensate for the disturbance.

The mouse population will remain stable as they adapt to the new environment.

Inputs are food sources, and outputs are waste products.

Inputs are births, and outputs are deaths.

Inputs are young animals, and outputs are old animals.

Inputs are predators, and outputs are prey.